Cardiovascular System - Blood vessels & heart Flashcards
Pulmonary artery
Takes deoxygenated blood away from the heart
Pulmonary vein
Takes oxygenated blood to the heart
Arteries
- No valves
- Handle high blood pressure
- 90 mmHg
Struture of artery
Tunica Interna (intima)
- Flat thin layer with smooth squamous endothelium (allow smooth flow of blood)
Struture of artery
Tunica Media
- Thick smooth muscle that contracts to restrict flow and it has elastic fibres
Struture of artery
Tunica externa
- Thick layer that has elastic tissue that strech in and out to handle the high pressure
Veins
- 75-80% saturation of oxygen
- Towards the heart
- Dark red in coulour
- Larger lumen compared to artery
Intima
the enothelia layer no elastic adventia
Externa
- Smooth muscle and elastic muscle
Valves
- Prevents back flow from high hydrostatic pressure to low opening the valve in one direction
Capillaries
- Network that connects the arteries and the veins
- Narrow lumen ensures diffusion rate is greater (thin endothelial cells continuously arranged for smooth flow
- In a muscular tissue to exchange nutrients
Intercellular cleft
- Material could be exchanged from the lumen of cappilary to tissues
Blood brain barrier
- Most tightly packed enothilial cell that are continous very small junctions meaning less toxins are able to enter
Fenestrated
- intestinal villi, kidney glomerili and endocrine cells these are highly permeable to larger biomolecules through fenestre
Sinusoid
- Red bone marroew and liver enabling larger molecule to prefuse protiens blood cells and waste
Pre-capillary
Vasoconstriction/dialation
- The bundles of smooth muscles pread out pre-cappilaries provides elasticity
Pre-capillaries
Sphincters
- Vasotone-dialation more blood to capillaries for metabolic demand such as exercise
Complex regulation
- metabolic demand
- Hormonal
- Temperature
Pericardial layer
- fluid layer helps to absorb the impact from dialation so it absorbs the shock so its not damages by the sternum
- provides elastisity
Myocardium
- Cardiac muscle that regulates the contraction and relaxing of muscle tissue
Edocardium
- inner layer of the heart
Septum
- protection from heart murmmurs by ensuring seperation between oxygenated and deoxygenated blood
Left side
Bicuspid valve
- From atrium to ventricle from high to low hydrostatic pressure
Tricuspid value
- Atrioventrical valve enables deoxyenadted oxygen from right atrium to right ventricle
right
Pulmonary valve
- Enables flow of blood from the right ventricle to the pulmonary artery
Aortic/semi-lunar valve
- Flows from the left ventricle to the aorta to pump blood the the rest of the body
Atrial kick
- Forceful open valve once atrium is filled in the bicuspid valve opens
Cardiac twist
- Both bicuspid and tricuspid laves close makes the lub sound
- When the semi-luner and the pulmonary valve close it makes a dub sound
Blood flow in artery
- Cardiac output
- Pressure (high to low)
- Gravitational pull
- Length & Diameter of artery
- Blood viscosity
Venous Return
- generate contraction to push blood towards the heart
- Calf/skeltal muscle pump coodinated movement from valves
- Pulsate arteries adjacent to the vein complement the muscle pressure and venous return
Venous Return
Respiratory and thoratic pump
breath in
- Diaphragam compress abdomen cavity increases the pressure and pushes blood from abdomen cavity to thorax
- Reduces pressure in thorax it sucks the blood from the abdominal cavity to thorax
Venous return
Respiratory and thoratic pump
Breath out
- Increased pressure in the thorax push the blood back in the heart
- Reduced pressure in the abdomen suck the blood from the lower part of the body
Coronary Circulation
- Two tiny arteries leaving out the aorta enabling oxyen to the heart
- Handles high pressure (irrespective of heart contraction or relaxation)
- Blockage leads to the major cardiac problem- Heart Attack
Microcirculation
- High hydrostatic pressure at the arteriole end of the capillary
- Small soluble substances such O2, CO2 other gases nutrients and metabolic waste
- Decrease in water potential and it has a high oncotic pressure
- Causes water to enter back in at the venule end to regulate the water potential
Vasoconstriction
Autoregulation of perfusion
- High oxygen and low levels of metabolic waste stimulates endothelial cells to release endothelin (peptides)
- Platelets & prostaglandins are secreated
- This causes the vasoconstriction of pre-capillary
Autoregulation of perfusion
Vasodialation
- Lower levels of O2 but highter levels of metabolic waste
- Stimulus endothelial cells to release Nitrous oxide vasodilation of precapillary
- Stretching of the smooth muscle in the walls of arterioles